Optical fiber coil unit for a fiber optic gyro

Abstract

A cylindrical bobbin having flanges at both ends thereof is formed as a unitary structure, using a material of thermal conductivity nearly equal to or lower than that of an optical fiber coil, and the optical fiber coil is wound on a housing portion defined between the flanges. An annular member is mounted on the bobbin to cover the housing portion on the outside of the optical fiber coil, forming an annular case for housing the optical fiber coil, together with the bobbin. The annular member is also made of a material which has a thermal conductivity nearly equal to or lower than that of the optical fiber coil.

What is claimed is: 
     
       1. An optical fiber coil unit for a fiber optic gyro comprising: an optical fiber coil:   a bobbin having said optical fiber coil wound thereon in a housing portion defined by flanges formed at opposite ends of said bobbin, said bobbin being made of a material which has a thermal conductivity nearly equal to or lower than that of the optical fiber of said optical fiber coil;   an end face of one of said flanges being fixed to a support plate; and   an annular member which covers said housing portion between said flanges on the outside of said housing portion to form an annular case, said annular member being made of a material which has a thermal conductivity nearly equal to or lower than that of said optical fiber.   
     
     
       2. An optical fiber coil unit for a fiber optic gyro comprising: an optical fiber coil;   a bobbin having said optical fiber coil wound thereon in a housing portion defined by flanges formed at opposite ends of said bobbin, said bobbin being made of a material which has a thermal conductivity nearly equal to or lower than that of the optical fiber of said optical fiber coil;   an annular member which covers said housing portion between said flanges on the outside of said housing portion to form an annular case, said annular member being made of a material which has a thermal conductivity nearly equal to or lower than that of said optical fiber;   leg means extended from the outer peripheral surface of said annular member and projecting outwardly from said flanges axially of said bobbin; and   a support plate disposed at a distance from said flanges, an end portion of said leg means being fixed to said support plate, said leg means having a thermal conductivity nearly equal to or lower than that of said optical fiber, and the cross-sectional area of said leg means in its radial direction being smaller than the outer surface area of said annular member.   
     
     
       3. An optical fiber coil unit for a fiber optic gyro comprising: an optical fiber coil;   a bobbin having said optical fiber coil wound thereon in a housing portion defined by flanges formed at opposite ends of said bobbin, said bobbin being made of a material which has a thermal conductivity nearly equal to or lower than that of the optical fiber of said optical fiber coil;   an annular member which covers said housing portion between said flanges on the outside of said housing portion to form an annular case, said annular member being made of a material which has a thermal conductivity nearly equal to or lower than that of said optical fiber;   leg means formed in contact with an end face of one of said flanges and having a diameter smaller than said flanges; and   a support plate disposed opposite said one flange, said leg means being interposed between said one flange and said support plate, said leg means having a thermal conductivity nearly equal to or lower than that of said optical fiber, and the cross-sectional area of said leg means in its radial direction being smaller than the area of said end face of said one flange.   
     
     
       4. The optical fiber coil unit of claim 1, 2 or 3 wherein said bobbin is formed as a unitary structure with said flanges, using ceramics.